Southern Red Muntjac, as defined here, occupy part of the Thai–Malay peninsula and occurs on the main islands of the Greater Sundas (Borneo, Java, Bali and Sumatra) and on various small islands (Chasen 1940; Groves 2003; Meijaard 2003). On Sumatra, it is not geographically limited to southern and eastern parts of the island despite various statements that it is (R.J. Timmins pers. comm. 2008). Taking the northern limit on the peninsula as the Isthmus of Kra (see Taxonomy), M. muntjak (as here defined) is assumed to inhabit southern Thailand and might be found to occur in southernmost Myanmar. It is now extinct in Singapore (Baker and Lim 2008).